How long is to long?
 

About fasting, ive been fasting for 40 hours now as i write this, how long is to long? im not hungry atm so i was just wondering. Im thinking of to long as for breaking down muscles etc.

Intermittent Fasting is typically around 24 hours or less. I go bout 18 hours usually when I fast.

I've heard of doing fasting for 24+ hours for detox purposes (water only) but IF you should still be trying to balance your total calories(at first) so if you did one day off then the next day you should try to eat more. If you fast 16 hours you just make eat the amount you regulary eat in the condense window.

I never go over 24 hours. Also there are factors like how many times you are doing this...how do you train...how much protein do you eat....etc. A long fast once in a great while is probably nothing to fear (like up to 48hours). But if you are not eating or training for muscle maintenance the rest of the time....don't expect it to stick around.

What I was told in school is that after 3 full days of water fasting, your body has run out of the most important amino acids that the liver needs for detoxification. This means that the body must dip into its own protein stores for these amino acids.

If I'm going to do a longer fast, I don't go longer than three days. I also watch for my hunger to get ravenous after the initial "calming" of the hunger signs. The reappearance of hunger (not just wanting to chew something, it's amazing how much I missed chewing on a water fast) is a good sign that the body is about done with the usefulness of that particular fast.

Might be worth noting that the great majority of animal research showing beneficial effects of intermittent fasting use 48 hour fasts.

Most of the research is actually ADF (alternate day fasting) which is about 36 hours. Some are 24 hours (more ADCR - alternate day calorie restriction). I would like to see more research on the compounding effects of more 18hr fasting daily.....but that probably wont happen anytime soon.

thank you. gonna implement some 36 hour fasts every now and then :) i feel like after a longer fast my appetite is much smaller, can get away with 1/2 of the food wich is a good thing for a BIG eater like me.

Oops, I was referring to ADF, but I forgot to take into account the time spend eating (animals are typically offered food for the entire 24 hours on alternate days). Unfortunately, researchers never report the actual feeding patterns of their subjects, so the actual fast (time from the last meal of one day to the first meal of the next feed day) might be as short as 24 hours. However, there is some evidence suggesting that animals may change their feeding habits to consume their daily intake in a relatively short time interval (~2 hours, more of a gorging pattern), so the fasts might be as long as 46 hours.

Yeah, and I agree that research on <24 hour fasting would be really interesting.

For me the limit is around 48 hours, on the third day my metabolism starts to shut down and I begin to freeze.